walker county 911

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medic9351301

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anybody know whats up with walker county 911 they used to have a north rept and as south rep both on the same fre of 159.390 with diff pl tones but now it seems like both rpts are on 1 freq with the same pl tone
 

morganAL

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Simulcast maybe? It would be the logical thing to do. I wish Forestry would do simulcast with receiver voting here. Volunteer fire has 4 repeaters and a 5th on the way. All on the same freq, just different PL tones.
 

morganAL

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It's a little more work and cost to set up but it is easier on those that use the system. It has its own issues as well. It takes more planning and sometimes different antenna patterns to move the TDI (time domain interference) into an area not used by the users and it requires connectivity between all of the sites. If you listen very close, if you can hear a little bit of beat cancellation in the audio, it is simulcast. Anyway, my $.02 thought for the day.
 

rbryant2

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Nothing quite that complex. In December, when the county fire association - which own's the repeaters that operate on this frequency - made the conversion to narrowband, the decision was made to change the output tones of the repeaters to a common tone. This allows all units in the county to hear all traffic on the frequency. In the past, there was occasionally issues when a unit operating on one repeater would not realize that there was traffic taking place on the other repeater. The repeaters continue to use seperate input tones, which allows the operator of the mobile unit to choose the repeater which give the best coverage in that particular location, but still hear traffic on the other repeater.
 

medic9351301

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ok thanks whats the narrow band freqs i have searched for them and can not find them also do you know whats up with dora pd used to hear both sides of the convers now on hearing the cars but still hear the repeater tone on the mobile side
 

rbryant2

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The county fire association's frequencies haven't changed. What you are hearing on the original frequenices is now being transmitted using narrow bandwidth - 12.5 kHz as opposed to 25 kHz. You shouldn't be able to tell much difference listening aside from a very modest reduction in audio level and maybe slightly reduced coverage area.
 
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